diff --git a/app/jobs/reports/deleted_user_accounts_report.rb b/app/jobs/reports/deleted_user_accounts_report.rb
index 53b8fc391df..214a4db1e50 100644
--- a/app/jobs/reports/deleted_user_accounts_report.rb
+++ b/app/jobs/reports/deleted_user_accounts_report.rb
@@ -19,13 +19,15 @@ def perform(_date)
         emails = report_hash['emails']
         issuers = report_hash['issuers']
         report = deleted_user_accounts_data_for_issuers(issuers)
+        # rubocop:disable IdentityIdp/MailLaterLinter
         emails.each do |email|
           ReportMailer.deleted_user_accounts_report(
             email: email,
             name: name,
             issuers: issuers,
             data: report,
-          ).deliver_now_or_later
+          ).deliver_now
+          # rubocop:enable IdentityIdp/MailLaterLinter
         end
       end
     end
diff --git a/app/mailers/user_mailer.rb b/app/mailers/user_mailer.rb
index af48c95fe45..5977ba5aa0d 100644
--- a/app/mailers/user_mailer.rb
+++ b/app/mailers/user_mailer.rb
@@ -22,6 +22,7 @@ class UserEmailAddressMismatchError < StandardError; end
 
   before_action :validate_user_and_email_address
   before_action :attach_images
+  after_action :add_metadata
   default(
     from: email_with_name(
       IdentityConfig.store.email_from,
@@ -43,6 +44,10 @@ def validate_user_and_email_address
     end
   end
 
+  def add_metadata
+    message.instance_variable_set(:@_metadata, { user: user, action: action_name })
+  end
+
   def email_confirmation_instructions(token, request_id:, instructions:)
     with_user_locale(user) do
       presenter = ConfirmationEmailPresenter.new(user, view_context)
diff --git a/app/services/analytics_events.rb b/app/services/analytics_events.rb
index 579995f89d1..3e1935e0bae 100644
--- a/app/services/analytics_events.rb
+++ b/app/services/analytics_events.rb
@@ -2978,5 +2978,17 @@ def idv_personal_key_acknowledgment_toggled(checked:, proofing_components:, **ex
       **extra,
     )
   end
+
+  # Logs after an email is sent
+  # @param [String] action type of email being sent
+  # @param [String, nil] ses_message_id AWS SES Message ID
+  def email_sent(action:, ses_message_id:, **extra)
+    track_event(
+      'Email Sent',
+      action: action,
+      ses_message_id: ses_message_id,
+      **extra,
+    )
+  end
 end
 # rubocop:enable Metrics/ModuleLength
diff --git a/app/services/db/service_provider_quota_limit/notify_if_any_sp_over_quota_limit.rb b/app/services/db/service_provider_quota_limit/notify_if_any_sp_over_quota_limit.rb
index 04f836ac0f5..2d662c3a98e 100644
--- a/app/services/db/service_provider_quota_limit/notify_if_any_sp_over_quota_limit.rb
+++ b/app/services/db/service_provider_quota_limit/notify_if_any_sp_over_quota_limit.rb
@@ -5,7 +5,9 @@ def self.call
         return unless Db::ServiceProviderQuotaLimit::AnySpOverQuotaLimit.call
         email_list = IdentityConfig.store.sps_over_quota_limit_notify_email_list
         email_list.each do |email|
-          ReportMailer.sps_over_quota_limit(email).deliver_now_or_later
+          # rubocop:disable IdentityIdp/MailLaterLinter
+          ReportMailer.sps_over_quota_limit(email).deliver_now
+          # rubocop:enable IdentityIdp/MailLaterLinter
         end
       end
     end
diff --git a/config/application.rb b/config/application.rb
index 703d4ac6ce7..d37be6d1246 100644
--- a/config/application.rb
+++ b/config/application.rb
@@ -12,9 +12,12 @@
 require_relative '../lib/identity_config'
 require_relative '../lib/fingerprinter'
 require_relative '../lib/identity_job_log_subscriber'
+require_relative '../lib/email_delivery_observer'
 
 Bundler.require(*Rails.groups)
 
+require_relative '../lib/mailer_sensitive_information_checker'
+
 APP_NAME = 'Login.gov'.freeze
 
 module Identity
@@ -93,6 +96,7 @@ class Application < Rails::Application
         mail.display_name = IdentityConfig.store.email_from_display_name
       end.to_s,
     }
+    config.action_mailer.observers = %w[EmailDeliveryObserver]
 
     require 'headers_filter'
     config.middleware.insert_before 0, HeadersFilter
diff --git a/config/initializers/ext_action_mailer.rb b/config/initializers/ext_action_mailer.rb
index 11cfbcceac1..3bdc843829b 100644
--- a/config/initializers/ext_action_mailer.rb
+++ b/config/initializers/ext_action_mailer.rb
@@ -1,8 +1,18 @@
 # Monkeypatches the MessageDelivery to add deliver_now_or_later that
 # can route between #deliver_now and #deliver_later
+module DeliverLaterArgumentChecker
+  def deliver_later(...)
+    MailerSensitiveInformationChecker.check_for_sensitive_pii!(@params, @args, @action)
+    super(...)
+  end
+end
+
 module ActionMailer
   class MessageDelivery
+    prepend DeliverLaterArgumentChecker
+
     def deliver_now_or_later(opts = {})
+      MailerSensitiveInformationChecker.check_for_sensitive_pii!(@params, @args, @action)
       # rubocop:disable IdentityIdp/MailLaterLinter
       if IdentityConfig.store.deliver_mail_async
         deliver_later(opts)
diff --git a/lib/aws/ses.rb b/lib/aws/ses.rb
index b65bea1c349..c80a77fbb22 100644
--- a/lib/aws/ses.rb
+++ b/lib/aws/ses.rb
@@ -9,9 +9,9 @@ class Base
       def initialize(*); end
 
       def deliver(mail)
-        response = ses_client.send_raw_email(raw_message: { data: mail.to_s })
-        mail.message_id = "#{response.message_id}@email.amazonses.com"
-        response
+        ses_client.send_raw_email(raw_message: { data: mail.to_s }).tap do |response|
+          mail.header[:ses_message_id] = response.message_id
+        end
       end
 
       alias deliver! deliver
diff --git a/lib/email_delivery_observer.rb b/lib/email_delivery_observer.rb
new file mode 100644
index 00000000000..eec394150e0
--- /dev/null
+++ b/lib/email_delivery_observer.rb
@@ -0,0 +1,9 @@
+class EmailDeliveryObserver
+  def self.delivered_email(mail)
+    metadata = mail.instance_variable_get(:@_metadata) || {}
+    user = metadata[:user] || AnonymousUser.new
+    action = metadata[:action]
+    Analytics.new(user: user, request: nil, sp: nil, session: {}).
+      email_sent(action: action, ses_message_id: mail.header[:ses_message_id]&.value)
+  end
+end
diff --git a/lib/mailer_sensitive_information_checker.rb b/lib/mailer_sensitive_information_checker.rb
new file mode 100644
index 00000000000..061dcf0297e
--- /dev/null
+++ b/lib/mailer_sensitive_information_checker.rb
@@ -0,0 +1,54 @@
+class MailerSensitiveInformationChecker
+  class SensitiveKeyError < StandardError; end
+
+  class SensitiveValueError < StandardError; end
+
+  def self.check_for_sensitive_pii!(params, args_array, action)
+    args = ActiveJob::Arguments.serialize(args_array)
+    serialized_params = ActiveJob::Arguments.serialize(params)
+    serialized_args_string = args.to_s
+    serialized_params_string = serialized_params.to_s
+
+    if params[:email_address].is_a?(EmailAddress)
+      check_hash(params.except(:email_address), action)
+    else
+      check_hash(params, action)
+    end
+    args.each do |arg|
+      next unless arg.is_a?(Hash)
+      check_hash(arg, action)
+    end
+
+    if SessionEncryptor::SENSITIVE_REGEX.match?(serialized_args_string)
+      self.alert(SensitiveValueError.new)
+    end
+
+    if SessionEncryptor::SENSITIVE_REGEX.match?(serialized_params_string)
+      self.alert(SensitiveValueError.new)
+    end
+  end
+
+  def self.check_hash(hash, action)
+    hash.deep_transform_keys do |key|
+      if SessionEncryptor::SENSITIVE_KEYS.include?(key.to_s)
+        exception = SensitiveKeyError.new(
+          "#{key} unexpectedly appeared in #{action} Mailer args",
+        )
+        self.alert(exception)
+      end
+    end
+  end
+
+  def self.alert(exception)
+    if IdentityConfig.store.session_encryptor_alert_enabled
+      NewRelic::Agent.notice_error(exception)
+    else
+      raise exception
+    end
+  end
+
+  class << self
+    include ::NewRelic::Agent::MethodTracer
+    add_method_tracer :check_for_sensitive_pii!, "Custom/#{name}/check_for_sensitive_pii!"
+  end
+end
diff --git a/spec/lib/aws/ses_spec.rb b/spec/lib/aws/ses_spec.rb
index 6d22ee5c12c..094f6405c16 100644
--- a/spec/lib/aws/ses_spec.rb
+++ b/spec/lib/aws/ses_spec.rb
@@ -35,7 +35,7 @@
 
     it 'sets the message id on the mail argument' do
       subject.deliver!(mail)
-      expect(mail.message_id).to eq('123abc@email.amazonses.com')
+      expect(mail.header['ses-message-id'].value).to eq('123abc')
     end
 
     it 'retries timed out requests' do
diff --git a/spec/mailers/previews/user_mailer_preview_spec.rb b/spec/mailers/previews/user_mailer_preview_spec.rb
index 5c6ac3ed4be..1ce068b8a33 100644
--- a/spec/mailers/previews/user_mailer_preview_spec.rb
+++ b/spec/mailers/previews/user_mailer_preview_spec.rb
@@ -13,7 +13,7 @@
   it 'has a preview method for each mailer method' do
     mailer_methods = UserMailer.instance_methods(false)
     preview_methods = UserMailerPreview.instance_methods(false)
-    mailer_helper_methods = [:email_address, :user, :validate_user_and_email_address]
+    mailer_helper_methods = [:email_address, :user, :validate_user_and_email_address, :add_metadata]
     expect(mailer_methods - mailer_helper_methods - preview_methods).to be_empty
   end
 
diff --git a/spec/mailers/user_mailer_spec.rb b/spec/mailers/user_mailer_spec.rb
index ec2287933be..1c377097d25 100644
--- a/spec/mailers/user_mailer_spec.rb
+++ b/spec/mailers/user_mailer_spec.rb
@@ -670,4 +670,31 @@ def expect_email_body_to_have_help_and_contact_links
         )
     end
   end
+
+  # rubocop:disable IdentityIdp/MailLaterLinter
+  describe '#deliver_later' do
+    it 'does not queue email if it potentially contains sensitive value' do
+      user = create(:user)
+      mailer = UserMailer.with(
+        user: user,
+        email_address: user.email_addresses.first,
+      ).add_email(Idp::Constants::MOCK_IDV_APPLICANT[:last_name])
+      expect { mailer.deliver_later }.to raise_error(
+        MailerSensitiveInformationChecker::SensitiveValueError,
+      )
+    end
+
+    it 'does not queue email if it potentially contains sensitive keys' do
+      user = create(:user)
+      mailer = UserMailer.with(user: user, email_address: user.email_addresses.first).add_email(
+        {
+          first_name: nil,
+        },
+      )
+      expect { mailer.deliver_later }.to raise_error(
+        MailerSensitiveInformationChecker::SensitiveKeyError,
+      )
+    end
+  end
+  # rubocop:enable IdentityIdp/MailLaterLinter
 end